I'm in the US and I wasn't aware they weren't allowed. What does that mean exactly? I know that official documents will leave them off and no one would ever remember it, but I don't think they are banned or anything.

Rge- we cannot put any diacritical marks on official documents like social security forms, passports, etc. Some states will let an occasional accent slide, but they are not allowed on birth certificates either. My future last name has an accent and since we cannot officially use it, my poor fiancé has had his name mispronounced his whole life. It's really annoying.